PARASITES

Question 1

parasitic phylums

Answer 1

protista, anamalia, nemathelminthes, arthropoda

Question 2

what is coevolution

Answer 2

two or more species having close evolutionary changes
inconsistencies due to host switching

Question 3

direct life cycle vs indirect

Answer 3

direct = one host only
indirect = deifnitive host, intermediate host

Question 4

why are parasites important

Answer 4

1. common
2. cause disease - threat to endangered
3. new diseases emerging due to enviro change
4. structure ecosystem - impact competitive interactions, genetic diversity, immune defence

Question 5

draw lifecycle of teania spp.

Answer 5

• tapeworm
• platyhelmintehs
• onchospheres

1. cattle and pigs ingest eggs in grass or in feaces
2. onchospheres hatch in intestine and circultate musculature
3. in muscles the onchospheres mature into cysts
4. humans eat meat with cysts and become infected, enters intestine
5. matrue inside intestine

Question 6

draw lifecycle of haemonchus contortus

Answer 6

1. adult worms lay eggs in faeces
2. in wet climate, eggs hatch
3. larvae migrate in wet climate to new pastures
4. larvae eaten by sheep and mature in abasum

Question 7

draw lifecycle of ctenocephalides felis

Answer 7

• eggs laid on dog
• first, second, third, stage of larvae
• pupa in silk coccoon
• adult
• type of arthropoda (insecta)

Question 8

draw lifecycle of echindococcus

Answer 8

dog - eggs in faeces - livestock eat eggs - dog eats livestock

• type of playhelminthes

Question 9

draw lifecycle of fasciola hepatica (fluke) - hard one

Answer 9

1.fluke produce eggs in feaces of mamals
2.eggs embryonate in right conditions
3.miracidia release from egg with enzymes
4.penetrate aquatic snail as a sporocyst and replicate into redia
5. redia leave snail as cercaria and attach to water plants/crops
6. eaten by mammals

platyhelminthe

Question 10

draw lifecycle of balantidium (strawberries)

Answer 10

type of ciliate
1. in large intestne of mammals, trophozoites replicate
2. trophozoites undergo encystation to produce inefective cysts, mature cysts are passed in feaces
3. ingested in contaminated food or drink (e.g. strawberries)

Question 11

draw lifecycle of malaria

Answer 11

1. infected anopheles (female) mosquito bites skin
2. sporozoites move into blood stream and infect liver cells
3. in liver cells, develop into schinzonts
4. they rupture and release merozoites into the blood stream
5. infect red blood cells and cause disease
6. some become gametocytes for another mosquito to ingest